Alert archive / Massachusetts / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 39, NWS Boston/Norton, MA

July 27, 2018Franklin County, Worcester County, Massachusetts

NWS Boston/Norton, MA issued this severe thunderstorm warning at Jul 27, 2018, 8:11 PM EDT for Franklin County, Worcester County, Massachusetts. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 27, 2018, 8:11 PM EDT (00:11 UTC)
Expired: Jul 27, 2018, 8:39 PM EDT
In force: 28 min
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Franklin County, MA, Worcester County, MA

The radar

The Boston radar (KBOX), 118 km from the middle of the area, began a volume at 00:14 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 27, 1:17 PM EDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 27, 1:31 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 0.2 hours before the alert went out and 130 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 495 J/kg
Mixed-layer CIN: -72 J/kg
Mixed-layer LCL: 1197 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted.

141 
WUUS51 KBOX 280011
SVRBOX
MAC011-027-280100-
/O.NEW.KBOX.SV.W.0039.180728T0011Z-180728T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Boston/Norton MA
811 PM EDT FRI JUL 27 2018

The National Weather Service in Boston/Norton has issued a

* Severe Thunderstorm Warning for...
  Northwestern Worcester County in central Massachusetts...
  Northeastern Franklin County in western Massachusetts...

* Until 900 PM EDT.

* At 810 PM EDT, a severe thunderstorm was located over Wendell, or
  near Orange, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines a tornado is also 
           possible.

* Locations impacted include...
  Orange, Athol, Winchendon, Montague, Templeton, Ashburnham,
  Northfield, Leverett, Erving, Shutesbury, Phillipston, Gill,
  Royalston, New Salem, Wendell and Warwick.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

Although a tornado is not immediately likely, it is best to move to 
an interior room on the lowest floor of a building. This storm may 
cause serious injury and significant property damage.

&&

LAT...LON 4271 7192 4246 7242 4259 7257 4272 7238
TIME...MOT...LOC 0010Z 229DEG 30KT 4257 7241 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

md

1 follow-up statement

753 
WWUS51 KBOX 280039
SVSBOX

Severe Weather Statement
National Weather Service Boston/Norton MA
839 PM EDT FRI JUL 27 2018

MAC011-027-280049-
/O.CAN.KBOX.SV.W.0039.000000T0000Z-180728T0100Z/
Worcester MA-Franklin MA-
839 PM EDT FRI JUL 27 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WORCESTER AND
NORTHEASTERN FRANKLIN COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
western Massachusetts. A Severe Thunderstorm Watch also remains in
effect until 1000 PM EDT for central Massachusetts.

LAT...LON 4271 7192 4246 7242 4259 7257 4272 7238
TIME...MOT...LOC 0038Z 229DEG 30KT 4273 7216 

$$

md

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 9:36 PM EDT	Special Weather Statement	BOX	Worcester	39 min
Jul 28, 5:24 PM EDT	Special Weather Statement	BOX	Franklin	51 min
Jul 28, 6:27 PM EDT	Special Weather Statement	BOX	Worcester	48 min

Nearby

Severe Thunderstorm Warnings in Massachusetts, 2018 Every severe thunderstorm warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.